Relay Apparatus and Relay Method

ABSTRACT

To provide a relay apparatus and a relay method by which an app can be flexibly connected to a device and various apps can be connected to various devices to realize stable operation. The invention is a relay method for mediating a connection between an app and a device, and the relay method includes: when an input specification of data required for an app whose use is to be started is input, comparing an output specification held by each processing node provided in an existing data processing path with a data item included in the input specification; connecting an output of the data processing path to the app whose use is to be started if the existing processing node and the existing data processing path are able to satisfy the input specification; adding a new processing node and comparing an output specification of the new processing node with the input specification if the existing data processing path is not able to satisfy the input specification; and connecting an output of the new processing node to the app whose use is to be started if the new processing node is able to satisfy the input specification.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a relay apparatus and a relay methodused for the same.

2. Description of the Related Art

There is JP-A-2017-167747 as a related art literature in the technicalfield. JP-A-2017-167747 discloses a method in which, based on an inputspecification of an application (hereinafter, abbreviated as an app) andoutput specifications of devices, a combination of devices satisfying arequest of the app is selected so as to connect the app and the device.

In order to provide apps that meet needs of various customers inenvironments such as factories of the various customers, it is necessaryto, when use of an app is to be started, appropriately select andconnect a device in an environment in which an input specification ofthe app can be satisfied. At this time, in a method in the related art,as in JP-A-2017-167747, in order to select a combination of devicessatisfying a request of an app, it is necessary to create the app suchas designing an input specification of the app according to an outputspecification of a device by making the app and the device correspond toeach other in a one-to-one manner, and man-hours are required forproviding various apps to the environments of the various customersaccording to the needs of the customers.

Therefore, it is desired that the app can be flexibly connected to thedevice by inserting a processing node between the app and the device andloosely coupling the app and the device, but in order to connect variousapps to various devices and stably operate the various apps, it isnecessary to efficiently operate the processing node on a relayapparatus that connects the app and the device.

SUMMARY OF THE INVENTION

In view of the above problems, an object of the invention is to providea relay apparatus and a relay method by which an app can be flexiblyconnected to a device and various apps can be connected to variousdevices to realize stable operation. The invention is, for example, arelay method for mediating a connection between an app and a device, andthe relay method includes: when an input specification of data requiredfor an app whose use is to be started is input, comparing an outputspecification held by each processing node provided in an existing dataprocessing path with a data item included in the input specification;connecting an output of the data processing path to the app whose use isto be started if the existing processing node and the existing dataprocessing path are able to satisfy the input specification; adding anew processing node and comparing an output specification of the newprocessing node with the input specification if the existing dataprocessing path is not able to satisfy the input specification; andconnecting an output of the new processing node to the app whose use isto be started if the new processing node is able to satisfy the inputspecification.

According to the invention, a relay apparatus and a relay method can beprovided by which an app can be flexibly connected to a device andvarious apps can be connected to various devices to realize stableoperation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a functional configuration diagram of a system to which arelay apparatus in an embodiment is applied.

FIG. 2 is a configuration example of a processing node management tablein the embodiment.

FIG. 3 is a configuration example of a device management table in theembodiment.

FIG. 4 is a configuration example of an app management table in theembodiment.

FIG. 5 is a configuration example of a data processing path managementtable in the embodiment.

FIG. 6 is a configuration example of a connection pattern managementtable in the embodiment.

FIG. 7 is a configuration example of a high use-frequency app managementtable in the embodiment.

FIG. 8 is a configuration example of a number-of-appearances managementtable in the embodiment.

FIG. 9A is a flowchart (1/3) of app connection processing in theembodiment.

FIG. 9B is a flowchart (2/3) of the app connection processing in theembodiment.

FIG. 9C is a flowchart (3/3) of the app connection processing in theembodiment.

FIG. 10 is a flowchart of connection node selection processing in theembodiment.

FIG. 11 is a flowchart of additional processing node selectionprocessing in the embodiment.

FIG. 12 is a flowchart of additional path selection processing in theembodiment.

FIG. 13 is a system configuration diagram (step 1) of a use case in theembodiment.

FIG. 14 is a system configuration diagram (step 2) of the use case inthe embodiment.

FIG. 15 is a system configuration diagram (step 3) of the use case inthe embodiment.

FIG. 16 is a system configuration diagram (step 4) of the use case inthe embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the invention will be described withreference to drawings.

Embodiment

The present embodiment relates to a relay apparatus that relays datafrom an on-site device in a factory or the like or data from a sensorattached to the on-site device, to an app provided by using an internetof things (IoT) platform in a cloud or an edge/fog. For example, therelay apparatus receives operating data from the on-site device orsensing data from the sensor and transmits the data to the app on thecloud in an environment in which various configured functions aredynamically provided and a configuration of software that dynamicallyexecutes the functions in operation with each other in anautonomous-decentralized manner changes. Further, when relay processingrequired for connecting an app that uses data with an on-site device ora sensor that provides the data is provided, by sharing the relayprocessing that has already been provided, many diverse apps areconnected to many on-site devices or sensors via the IoT platform and asystem as a whole is stabilized and scalable to provide highoperability.

FIG. 1 is a functional configuration diagram of a system targeted by therelay apparatus in the present embodiment. As shown in FIG. 1, in thesystem, apps 1000, 1100, and 1200 that perform advanced analysisprocessing or the like in a computer environment such as a cloud aredeployed, and input specifications 1001, 1101, 1201, and 1202 thatspecify specifications of data to be received are defined for therespective apps. In addition, machine tools, or devices 3000, 3100, and3200 are installed in a manufacturing site such as a factory, and outputspecifications 3010, 3110, and 3210 that specify specifications of datato be output are defined for the respective devices. The respective appsand the respective devices are connected to each other via a relayapparatus 5000.

In order to connect the apps 1000 to 1200 with the devices 3000 to 3200to realize data exchange, the relay apparatus 5000 is provided withprocessing nodes 2000 to 2600 for matching (hereafter, “match” is usedin the same meaning as “satisfy”) the input specifications 1001 to 1202of the respective apps 1000 to 1200 with the output specifications 3010to 3210 of the devices to be connected by adjusting or converting thesespecifications. For the processing nodes 2000 to 2600, inputspecifications 2001 to 2601 that specify specifications of data to bereceived by the processing nodes are defined, and output specifications2010 to 2620 that specify specifications of data to be output aredefined.

Further, in the apps 1000 to 1200, the processing nodes 2000 to 2600,and the devices 3000 to 3200, those having the input specifications andthe output specifications whose contents match each other can beconnected to each other.

In FIG. 1, the relay apparatus 5000 is described as a processinginfrastructure 5100 that is a common function for executing theseprocessing nodes, and a storage unit 5200 that stores programsfunctioning as the processing nodes that depend on the apps and thedevices and are not generalized.

The processing infrastructure 5100 includes: a device management unit5101 that manages the devices installed in the site and connected to theapps; an app management unit 5102 that manages the apps executed in acloud or an on-premises environment and connected to the devices; aprocessing node management unit 5103 that manages the processing nodesthat relay and connect the apps and the devices; and a data processingpath management unit 5104 that manages a connection relationship of theprocessing nodes that relay the apps and the devices to transmit thedata.

Processing of executing the processing nodes 2000 to 2600 stored in thestorage unit 5200 is executed by executing app connection processingperformed by an app connection processing unit (not shown) incooperation with processing performed by the processing infrastructure5100.

In addition, as a hardware image of the relay apparatus 5000, the relayapparatus 5000 is implemented by an apparatus which is a generalinformation processing apparatus and includes a processing device (CPU),a storage device (memory), and an input and output interface (I/F). Thatis, the processing performed by the processing infrastructure 5100 andthe app connection processing that is the processing of executing theprocessing nodes 2000 to 2600 stored in the storage unit 5200 isexecuted by the CPU performing software processing based on the data andthe programs for processing those processing nodes stored in the storagedevice that is the storage unit 5200. Image processing may be executedby a graphics processing unit (GPU). In addition, the app and the deviceare connected via the I/F.

FIG. 2 is a configuration example of a processing node management tableT100 held by the processing node management unit 5103 in the presentembodiment. The processing node management table T100 is a table thatmanages attributes of processing nodes currently being executed by therelay apparatus. As shown in FIG. 2, the processing node managementtable T100 includes the following attributes related to the processingnodes being currently operated in the relay apparatus: an internallyassigned serial number T101; a name T102 of a processing node; thenumber of input specifications T103 of the processing node; an inputspecification T104 including a data item T105 and an input frequencyT106 of data in the processing node; the number of output specificationsT107 of the processing node; and an output specification T108 includinga data item T109 and an output frequency T110 of data in the processingnode.

FIG. 3 is a configuration example of a device management table T200 heldby the device management unit 5101 in the present embodiment. The devicemanagement table T200 is a table that manages on-site devices currentlyaccommodated by the relay apparatus. As shown in FIG. 3, the devicemanagement table T200 includes an internally assigned serial numberT201, a name T202 of a device, the number of output specifications T203of the device, and an output specification T204 including a data itemT205 and an output frequency T206 of data in the device.

FIG. 4 is a configuration example of an app management table T300 heldby the app management unit 5102 in the present embodiment. The appmanagement table T300 is a table that manages apps that operate in thecloud or the on-premises environment and are currently accommodated bythe relay apparatus. As shown in FIG. 4, the app management table T300includes an internally assigned serial number T301, a name T302 of anapp, the number of input specifications T303 of the app, and an inputspecification T304 including a data item T305 and an input frequencyT306 of data in the app.

FIG. 5 is a configuration example of a data processing path managementtable T400 held by the data processing path management unit 5104 in thepresent embodiment. As shown in FIG. 5, the data processing pathmanagement table T400 includes: an internally assigned serial numberT401; a name T402 of an app, a processing node, or a device; the numberof inputs T403 indicating the number of connections on an input sidewhere the app, the processing node, or the device permits connection; aninput source #T404 indicating a serial number that identifies aprocessing node or a device currently connected to the app, theprocessing node, or the device; the number of outputs T405 indicatingthe number of connections on an output side where the processing node orthe device permits connection; and an output destination #T406indicating a serial number that identifies a processing node or an appcurrently connected to the processing node or the device.

FIG. 6 is a configuration example of a connection pattern managementtable T500 managed by the processing infrastructure 5100 in the presentembodiment. The connection pattern management table T500 is a table formanaging combinations in which the relay apparatus can connect an appand a device via a processing node. As shown in FIG. 6, the connectionpattern management table T500 includes: a connection pattern #T501 thatis internally assigned and identifies a connection pattern; a name T502of an app, a processing node, or a device that is a constituent of eachconnection pattern; #T503 indicating identifiers internally assigned tothe app, the processing node, or the device that is a constituent of theconnection pattern; an input source #T504 indicated by #T503 of an app,a processing node, or a device connected to an input side of the app,the processing node, or the device that is a constituent of eachconnection pattern; and an output destination #T505 indicated by #T503of a processing node or a device connected to an output side of the appor the processing node that is a constituent of each connection pattern.

FIG. 7 is a configuration example of a high use-frequency app managementtable T600 managed by the processing infrastructure 5100 in the presentembodiment. The high use-frequency app management table T600 is a tablefor managing apps used with a high frequency in sites having features,when the sites where the apps are used, for example, manufacturingsites, are classified according to features such as whether a target isa mass-produced product or a custom-made product, whether the target ishigh-mix low-volume production or low-mix mass production, and whetherthe target is line production, cell production, or job-shop production.As shown in FIG. 7, the high use-frequency app management table T600includes a site category #T601 that identifies each category, and a nameT602 of an app having a high use frequency in the site in the category.

FIG. 8 is a configuration example of a number-of-appearances managementtable T700 managed by the processing infrastructure 5100 in the presentembodiment. The number-of-appearances management table T700 is a tablefor managing effective connection patterns in a specific site, and theeffective connection patterns are obtained by, when on-site devices thatcan be used in the site are clarified and apps having a high usefrequency are clarified based on the features of the site, extracting,from the connection pattern management table T500, combinations in whichthe relay apparatus can connect apps that are expected to have a highuse frequency in the site with devices that can be used in the site. Asshown in FIG. 8, the number-of-appearances management table T700includes: an effective connection pattern #T701 that is an ID which isinternally assigned and identifies an effective connection pattern inthe site; a name T702 of the app, the processing node, or the devicethat is a constituent of each effective connection pattern; #T703indicating an identifier internally assigned to the app, the processingnode, or the device; an input source #T704 indicated by #T703 of theapp, the processing node, or the device connected to the input side ofthe app, the processing node, or the device that is a constituent ofeach effective connection pattern; an output destination #T705 indicatedby #T703 of the processing node or the device connected to the outputside of the app or the processing node that is a constituent of eacheffective connection pattern; and the number of appearances T706indicating the number of times the processing node or the deviceindicated by the name T702 appears in all of the effective connectionpatterns of the number-of-appearances management table T700. Aprocessing node or a device in which the number of appearances T706 hasa large numerical value is highly likely to be used in the site, and ishighly likely to be shared among a plurality of apps or a plurality ofdevices.

FIGS. 9A, 9B, and 9C show a flowchart P100 of app connection processingwhen the relay apparatus in the present embodiment connects an app and adevice. FIGS. 9A, 9B, and 9C form one continuous processing flowchart,which is divided into three drawings and shown because of spacelimitations.

In the app connection processing, first, as shown in FIG. 9A, it ischecked whether or not the app whose use is to be started can beconnected to a processing node that has already been operated in therelay apparatus. Next, as shown in FIG. 9B, if the app whose use is tobe started cannot be connected to the processing node being currentlyoperated, a new processing node is added and it is checked whether ornot a device already used in the relay apparatus cannot be used. Then,as shown in FIG. 9C, if the device already used in the relay apparatuscannot be used, it is checked whether or not the app cannot be connectedto another device registered in the relay apparatus. Hereinafter, theprocessing will be described in detail.

In FIG. 9A, first, in step S101, when the app is to be provided to asite where the device accommodated by the relay apparatus is installed,an input specification of the app whose use is to be started is input.Next, in step S102, a memory that stores processing nodes serving ascandidates to which the app whose use is to be started can be connectedis cleared. Then, between step S103 and step S106, the following stepsS104 and S105 are repeated for all processing nodes registered in thedata processing path management table T400. That is, in step S104,comparison is made to determine whether or not an output specificationof the processing node registered in the data processing path managementtable T400 matches the input specification, that is, the data item orthe frequency of the app whose use is to be started. Further, if theoutput specification of the processing node registered in the dataprocessing path management table T400 matches the input specification ofthe app whose use is to be started, in step S105, an identifier of theprocessing node is stored in the memory that stores the processing nodesserving as the candidates to which the app whose use is to be startedcan be connected.

Then, in step S107, it is evaluated whether or not a processing nodeserving as a candidate to which the app is connected is stored in thememory that stores the processing nodes serving as the candidates towhich the app whose use is to be started can be connected. If theprocessing node serving as the candidate is stored, the processingproceeds to step S108, and connection node selection processing P200 iscalled. Details of the connection node selection processing P200 will bedescribed later. Then, in step S109, the app is connected to theselected processing node, and the app connection ends (step S110).

If the processing node serving as the candidate is not stored in stepS107, in step S111, it is evaluated whether or not there is a processingnode that satisfies the input specification of the app whose use is tobe started among the processing nodes registered in the relay apparatus.Then, if there is a processing node that satisfies the inputspecification of the app among the registered processing nodes, theprocessing proceeds to step S116 in FIG. 9B. If there is no processingnode that satisfies the input specification of the app among theregistered processing nodes, the processing proceeds to step S112, andit is evaluated whether or not there is no device that satisfies theinput specification of the app among the devices registered in the relayapparatus. If there is no device that satisfies the input specificationof the app, the processing proceeds to step S114, the app whose use isto be started is determined to be unusable in the site where the relayapparatus operates, and the result is displayed. If there is a devicethat satisfies the input specification of the app, the processingproceeds to step S113, and the app whose use is to be started isdirectly connected to the corresponding device. Then, the processingproceeds to step S115, and the app connection ends.

In FIG. 9B, in step S116, the memory that stores the processing nodesserving as the candidates to which the app whose use is to be startedcan be connected is cleared. Further, in step S117, a memory that storesexisting processing nodes to which the new processing node forconnecting the app whose use is to be started can be connected iscleared. Then, between step S118 and step S121, the following steps S119and S120 are repeated for all the processing nodes registered in therelay apparatus. That is, in step S119, it is evaluated whether or notthe input specification of the app whose use is to be started matchesthe output specification of the processing node. If the inputspecification of the app whose use is to be started matches the outputspecification of the processing node, in step S120, an identifier of theprocessing node is stored in the memory that stores the processing nodesserving as the candidates to which the app whose use is to be startedcan be connected.

Then, between step S122 and step S127, processing between step S123 andstep S126 is repeated for all the processing nodes registered in thedata processing path management table T400.

In the processing between step S123 and step S126, processing of stepS124 and step S125 is repeated while there is a processing node matchingthe input specification of the app whose use is to be started from amongthe processing nodes registered in the relay apparatus. That is, in stepS124, it is evaluated whether or not the output specification of theprocessing node registered in the data processing path management tableT400 matches an input specification of the processing node matching theinput specification of the app whose use is to be started from among theprocessing nodes registered in the relay apparatus. Then, if the outputspecification of the processing node registered in the data processingpath management table T400 matches the input specification of theprocessing node matching the input specification of the app whose use isto be started from among the processing nodes registered in the relayapparatus, in step S125, an identifier of the processing node having theoutput specification matching the input specification of the app, and anidentifier of the processing node that is registered in the dataprocessing path management table T400 and has the output specificationmatching the input specification of the processing node, are stored inan additional processing node connection candidate list.

Then, in step S128, it is evaluated whether or not a processing nodeserving as a candidate is stored in the additional processing nodeconnection candidate list. Then, if the processing node serving as thecandidate is not stored, the processing proceeds to step S132 in FIG.9C. If the processing node serving as the candidate is stored, theprocessing proceeds to step S129, and additional processing nodeselection processing P300 is called using information of theseprocessing nodes serving as the candidates. Details of the additionalprocessing node selection processing P300 will be described later. Then,in step S130, the app is connected using information of the selectedprocessing node to be added and the existing processing node to whichthe processing node is to be connected, and the app connection ends(step S131).

In FIG. 9C, a new path in which the app and the device are relayed viaone or two processing nodes is searched for. First, in step S132, thememory that stores the processing nodes serving as the candidates towhich the app whose use is to be started can be connected is cleared. Inaddition, in step S133, a memory that stores candidates of a path to benewly added for connecting the app whose use is to be started iscleared.

Next, between step S134 and step S141, processing of step S135 andprocessing between step S136 and step S140 is repeated for all theprocessing nodes registered in the relay apparatus.

In the processing of step S135, it is evaluated whether or not the inputspecification of the app whose use is to be started matches the outputspecification of the processing node, and if the input specification ofthe app whose use is to be started matches the output specification ofthe processing node, the processing between step S136 and step S140 isrepeated. If the input specification of the app and the outputspecification of the processing node do not match, the processing ofstep S135 is repeated for a next processing node registered in the relayapparatus.

In the processing between step S136 and step S140, processing of stepS137, step S138, and step S139 is repeated the number of timescorresponding to the number of devices in the relay apparatus that canbe used. That is, in step S137, it is evaluated whether or not the inputspecification of the processing node whose output specification matchesthe input specification of the app whose use is to be started matchesthe output specification of the device. Then, if the input specificationof the processing node matches the output specification of the device,in step S138, a combination of the processing node and the device isstored in an additional path candidate list. If the input specificationof the processing node does not match the output specification of thedevice, in step S139, the combination of the processing node and thedevice is stored in an additional processing node candidate list.

Next, between step S142 and step S148, processing of step S143 andprocessing between step S144 and step S147 is repeated for allprocessing nodes stored in the additional processing node candidatelist.

In the processing of step S143, it is evaluated whether or not an inputspecification of the processing node stored in the additional processingnode candidate list matches the output specification of the processingnode registered in the relay apparatus, and if the input specificationof the processing node stored in the additional processing nodecandidate list matches the output specification of the processing noderegistered in the relay apparatus, the processing between step S144 andstep S147 is repeated. If the input specification of the processing nodestored in the additional processing node candidate list does not matchthe output specification of the processing node registered in the relayapparatus, the processing of step S143 is repeated for a next processingnode stored in the additional processing node candidate list.

In the processing between step S144 and step S147, processing of stepS145 and step S146 is repeated the number of times corresponding to thenumber of devices in the relay apparatus that can be used. That is, instep S145, it is evaluated whether or not the input specification of theprocessing node whose output specification matches the inputspecification of the processing node stored in the additional processingnode candidate list matches the output specification of the device.Then, if the input specification of the processing node matches theoutput specification of the device, in step S146, a combination of theprocessing node and the device is stored in the additional pathcandidate list.

Then, in step S149, it is evaluated whether or not a list in whichadditional path candidates for connecting the app whose use is to bestarted are stored is empty. If the list in which the additional pathcandidate is stored is not empty, the processing proceeds to step S150,and additional path selection processing P400 is called. Details of theadditional path selection processing P400 will be described later. Then,in step S152, a selected path is added to the relay apparatus and theapp is connected. If the list in which the additional path candidatesare stored is empty, in step S151, the app whose use is to be started isdetermined to be unusable in the site where the relay apparatusoperates, and the result is displayed. Then, the app connectionprocessing ends (step S153).

FIG. 10 is a flowchart of the connection node selection processing P200shown in step S108 in FIG. 9A in the present embodiment. The connectionnode selection processing P200 is to select, in the relay apparatus, aprocessing node that is most likely to be shared, among existingprocessing nodes used for connecting the app whose use is to be started.

In FIG. 10, first, in step S201, a memory that stores identifiers of theprocessing nodes used for connecting the app whose use is to be startedis cleared. In addition, in step S202, in order to select a processingnode that is most likely to be shared from a plurality of candidates,the maximum number of appearances in a memory that stores the number ofappearances calculated for each processing node is set to zero.

Then, between step S203 and step S207, the following steps S204, S205,and S206 are repeated for a plurality of processing node candidates thatcan be used for connecting the app whose use is to be started and aregenerated when the processing is called. That is, in step S204, thenumber of appearances of the processing node candidate is compared withthe maximum number of appearances. Then, if the number of appearances ofthe processing node candidate is larger than the maximum number ofappearances, in step S205, an identifier of the processing node isstored in the memory that stores the identifiers of the processing nodesused for connecting the app whose use is to be started. Further, in stepS206, the maximum number of appearances is updated with the number ofappearances of the processing node.

If the number of appearances of the processing node candidate is notlarger than the maximum number of appearances in step S204, processingof step S204 is repeated for a next processing node candidate. Then, instep S208, connection node selection ends.

FIG. 11 is a flowchart of the additional processing node selectionprocessing P300 shown in step S129 in FIG. 9B in the present embodiment.The additional processing node selection processing P300 is to select,in the relay apparatus, a processing node that is most likely to beshared, among processing nodes to be added for connecting the app whoseuse is to be started.

In FIG. 11, first, in step S301, a memory that stores identifiers of theprocessing nodes to be added for connecting the app whose use is to bestarted is cleared. In addition, in step S302, in order to select aprocessing node that is most likely to be shared from a plurality ofcandidates, the maximum number of appearances in a memory that storesthe number of appearances calculated for each processing node is set tozero.

Then, between step S303 and step S307, the following steps S304, S305,and S306 are repeated for a plurality of processing node candidates thatcan be added for connecting the app whose use is to be started and aregenerated when the processing is called. That is, in step S304, thenumber of appearances of the processing node candidate is compared withthe maximum number of appearances. Then, if the number of appearances ofthe processing node candidate is larger than the maximum number ofappearances, in step S305, an identifier of the processing node isstored in the memory that stores the identifiers of the processing nodesto be added for connecting the app whose use is to be started. Further,in step S306, the maximum number of appearances is updated with thenumber of appearances of the processing node.

If the number of appearances of the processing node candidate is notlarger than the maximum number of appearances in step S304, processingof step S304 is repeated for a next processing node candidate. Then, instep S308, additional processing node selection ends.

FIG. 12 is a flowchart of the additional path selection processing P400shown in step S150 in FIG. 9C in the present embodiment. The additionalpath selection processing P400 is to select, in the relay apparatus, apath to be added for connecting the app whose use is to be started.

In FIG. 12, first, in step S401, a memory that stores scores forcandidates of paths to be added for connecting the app whose use is tobe started is cleared to zero.

Then, between step S402 and step S407, processing between step S403 andstep S406 is repeated for a list of the candidates of the path to beadded for connecting the app whose use is to be started.

In the processing between step S403 and step S406, processing of stepS404 and step S405 is repeated for an existing data processing path foreach candidate of the path to be added. That is, in step S404, it isevaluated whether or not an output specification of a processing nodeconstituting the candidate of the path matches an input specification ofa processing node constituting the existing data processing path. Then,if the output specification of the processing node constituting thecandidate of the path matches the input specification of the processingnode constituting the existing data processing path, in step S405, ascore of the candidate of the path is incremented in the memory thatstores the scores for the candidates of the path to be added forconnecting the app whose use is to be started.

If the output specification of the processing node constituting thecandidate of the path does not match the input specification of theprocessing node constituting the existing data processing path in stepS404, the processing of step S404 is repeated for a next existing dataprocessing path.

Then, in step S408, a candidate having the highest score among thecandidates of the path to be added for connecting the app whose use isto be started is selected as the path to be added this time, andadditional path selection ends (step S409).

FIGS. 13, 14, 15, and 16 show a stepwise change of a use case where anapp and a device are connected via the relay apparatus in the presentembodiment.

FIG. 13 shows a situation where a work instruction app C1000 isconnected to a web camera C3000 via the relay apparatus 5000. The workinstruction app C1000 has an input specification C1001 includingpresence or absence of a worker as a data item. The web camera C3000 hasan output specification including H.264 as a data item. In order toconnect the web camera C3000 and the work instruction app C1000, therelay apparatus 5000 is provided with: a processing node C2000 thatdetermines presence or absence of a worker, has an input specificationC2001 including a still image as a data item and 1 fps as an inputfrequency, and has an output specification C2010 including the presenceor absence of a worker as a data item; and a processing node C2100 thatcuts out a still image at a low rate, has an input specification C2101including H.264 as a data item, and has an output specification C2110and an output specification C2120 including the still image as a dataitem and 0.1 fps and 1 fps as output frequencies.

FIG. 14 shows a situation where a work status visualization app C1100 isfurther added and used in an environment in FIG. 13. The work statusvisualization app C1100 has an input specification C1101 including thenumber of workers as a data item. Therefore, in order to connect thework status visualization app C1100, a processing node C2200 thatmeasures the number of workers, has an input specification C2201including a still image as a data item and 1 fps as an input frequency,and has an output specification C2210 including the number of workers asa data item is added to the relay apparatus 5000. At this time, theprocessing node C2200 that measures the number of workers uses, as aprocessing node to be connected as an input thereof, the processing nodeC2100 that cuts out the still image at a low rate and to which thein-operation processing node C2000 that determines the presence orabsence of a worker is connected, thereby an amount of processingaccompanying adding of the app is reduced, thus a time until the app canbe used is shortened, and at the same time, efficient operation isrealized by sharing resources in the relay apparatus 5000.

FIG. 15 shows a situation where a worker flow line visualization appC1200 is further added and used in an environment in FIG. 14. The workerflow line visualization app C1200 has an input specification C1201including a motion trajectory of a worker as a data item. Therefore, inorder to connect the worker flow line visualization app C1200, aprocessing node C2300 that extracts a motion trajectory of a worker, hasan input specification C2301 including a still image as a data item and10 fps as an input frequency, and has an output specification C2310including a motion trajectory of a worker as a data item is added to therelay apparatus 5000. However, since a processing node that satisfiesthe input specification of the processing node C2300 is not currentlyoperated, a processing node C2400 that cuts out a still image at amedium rate, can be connected to the web camera C3000, has an inputspecification C2401 including H.264 as a data item, and has an outputspecification C2410 and an output specification C2420 including a stillimage as a data item and 1 fps and 10 fps as output frequencies is addedto the relay apparatus 5000. As a result, the worker flow linevisualization app C1200 can be provided.

In addition, in an environment in FIG. 15, the processing node C2400that cuts out the still image at a medium rate and is added forconnecting the worker flow line visualization app C1200, can also beused as inputs of the processing node C2000 that determines the presenceor absence of a worker and the processing node C2200 that measures thenumber of workers, which are respectively connected to the workinstruction app C1000 and the work status visualization app C1100 thatare already provided. Therefore, FIG. 16 shows a situation where theprocessing node C2100 that cuts out the still image at a low rate andhas been connected as the inputs of the processing nodes C2000 and C2200is switched to the processing node C2400. As a result, the processingnode C2100 that cuts out the still image at a low rate is deleted fromthe storage unit 5200 of the relay apparatus 5000 because there is noprocessing node and app that use an output of the processing node C2100.Thus, by promoting sharing of the processing node added duringoperation, stable and efficient operation of the relay apparatus isrealized.

Thus, according to the present embodiment, in the relay apparatus, theprocessing node mediating a connection between the app and the device isinserted to realize loose coupling, and the processing node is operatedefficiently, and thereby a relay apparatus and a relay method used forthe relay apparatus can be provided by which an app can be flexiblyconnected to a device and various apps can be connected to variousdevices to realize stable operation. The embodiment has been describedabove, but the invention is not limited to the embodiment describedabove, and includes various modifications. For example, the embodimentsdescribed above have been described in detail for easy understanding ofthe invention, and the invention is not necessarily limited to thoseincluding all components described above.

What is claimed is:
 1. A relay method for mediating a connection betweenan app and a device, the relay method comprising: when an inputspecification of data required for an app whose use is to be started isinput, comparing an output specification held by each processing nodeprovided in an existing data processing path with a data item includedin the input specification; connecting an output of the data processingpath to the app whose use is to be started if the existing processingnode and the existing data processing path are able to satisfy the inputspecification; adding a new processing node and comparing an outputspecification of the new processing node with the input specification ifthe existing data processing path is not able to satisfy the inputspecification; and connecting an output of the new processing node tothe app whose use is to be started if the new processing node is able tosatisfy the input specification.
 2. The relay method according to claim1, further comprising: adding a new data processing path if the newprocessing node is not able to satisfy the input specification;comparing an output specification held by a processing node provided inthe new data processing path with the input specification; andconnecting an output of the new data processing path to the app whoseuse is to be started if the processing node provided in the new dataprocessing path is able to satisfy the input specification.
 3. The relaymethod according to claim 2, further comprising: determining that thedevice and the app whose use is to be started are not able to beconnected and displaying the result if the processing node provided inthe new data processing path is not able to satisfy the inputspecification.
 4. The relay method according to claim 1, wherein in thecomparing, the output specification held by the each processing nodeprovided in the existing data processing path is compared with afrequency in addition to the data item included in the inputspecification.
 5. The relay method according to claim 1, furthercomprising: during determination of the new processing node to be added,selecting a processing node from those in which the number ofappearances is high in order to specify a processing node that isexpected to be used in the future.
 6. A relay apparatus that mediates aconnection between an app and a device, the relay apparatus comprising:a processing device; a storage device; and an input and outputinterface, wherein the processing device is configured to: when an inputspecification of data required for an app whose use is to be started isinput via the input and output interface, compare an outputspecification held by each processing node provided in an existing dataprocessing path stored in the storage device with a data item includedin the input specification, connect an output of the data processingpath to the app whose use is to be started if the existing processingnode and the existing data processing path are able to satisfy the inputspecification, add a new processing node and compare an outputspecification of the new processing node with the input specification ifthe existing data processing path is not able to satisfy the inputspecification, and connect an output of the new processing node to theapp whose use is to be started if the new processing node is able tosatisfy the input specification.
 7. The relay apparatus according toclaim 6, wherein the processing device is configured to: add a new dataprocessing path via the input and output interface if the new processingnode is not able to satisfy the input specification, compare an outputspecification held by a processing node provided in the new dataprocessing path with the input specification, and connect an output ofthe new data processing path to the app whose use is to be started ifthe processing node provided in the new data processing path is able tosatisfy the input specification.
 8. The relay apparatus according toclaim 7, wherein the processing device is configured to: determine thatthe device and the app whose use is to be started are not able to beconnected and display the result if the processing node provided in thenew data processing path is not able to satisfy the input specification.9. The relay apparatus according to claim 6, wherein the processingdevice is configured to: as the comparison, compare the outputspecification held by the each processing node provided in the existingdata processing path with a frequency in addition to the data itemincluded in the input specification.
 10. The relay apparatus accordingto claim 6, wherein the processing device is configured to: duringdetermination of the new processing node to be added, select aprocessing node from those in which the number of appearances is high inorder to specify a processing node that is expected to be used in thefuture.